SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ff9a963ea5a7f700897969dbb5e5349db5fe9c431213890ecf98e45ec08f8ee5' 
  AND token = '6SeVUa/H1zKsanTIQ/Ivlaxj1wVkMUUHtxRmbATYGs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}